Gravity Calculations

[jonrober]

FYI: I am an extract brewer who is going/researching AG. Here is my AG question...

If I know my OG after boil is to be 1.050 and my evaporation rate is for example 15%/hr, how do I calculate what my wort gravity should be before the boil? Am I over thinking this?!?

Another question please...

If I miss my target gravity after boil, can I merely add some DME to compensate?

Here is an example after boil:
Have 5 Gallons of wort with a gravity of 1.045
My target gravity is 1.060

What type of calculation/modification is needed to compensate with DME?

I guess, since the wort is already boiled, I would have to add in another gallon of water to the mix because I would have to boil the added DME correct?

I really think I'm over thinking this and perhaps bothering you guys with these types of questions. Hope not!

Thanks!

[jonrober]

Almost forgot my original question.

What percentage of water does grain absorb? Have to calculate for that also

[HeathS]

There some pretty good recipe calculators here

www.tastybrew.com

[Lufah]

I'm with Heath. Get a copy of Promash or Beersmith. That or use an online calculator. The programs are only ~$20.

Travis

[jonrober]

Thanks for the info. I will pick up a program!

[Dogger Dan]

I am fond of Beer Smith

Just think, I used to do that by hand once

Dogger

[pvignola]

There are some calculations you can use if you want to do the math. Check out http://howtobrew.com if you want to know the math behind it. I have both Promash and Beersmith and I prefer just to be lazy and use one of them.

[Dr Scott]

Ray Daniels' "Designing great beers" is one of my favorite books. He explains the math and process pretty well in chapter 6
Cheers,
Dr Scott